1. Field of the Invention
The present invention relates to an oil recovering apparatus utilizing used lubricant from machines, more particularly to an oil recovering apparatus which uses a synchronizing mechanism to drive the scraping blades and the tank simultaneously at different rates, thereby enabling the scraping blades to scrape the contaminant from the inner wall of the tank and thus obtain an economical high degree of removal of contaminants.
2. Description of the Prior Art
In order to ensure smooth operation of a machine in a factory, it is often necessary to add lubricant or cooling oil to the machine as the machine is performing. For example, the manufacture of bolts or rivets involves a process of plastic deformation by means of high speed pressing requiring the addition of a large quantity of lubricant or cooling oil to operate the machine. However, since the quantity of oil added is extremely large and the used oil usually contains a large amount of contaminants, it causes pollution to the environment as well as increasing the costs of manufacture if the used oil is discarded. For environmental consideration and for the sake of cost-saving, an oil recovering apparatus is employed to separate the contaminant from the used oil or lubricant and recycle the oil or lubricant.
A conventional oil recovering apparatus is shown in FIG. 1, which is composed of a driving unit (1), a retaining means (2) and an oil-purifying mechanism (3). The oil-purifying mechanism (3) comprises a tank (17) for receiving used lubricant. An oil inlet (35) is provided at the bottom of the tank (17). A shaft seat (15) and a stopping member (16) are mounted together by a bolt (152) and then are sealed at the top of the tank (17) by bolts (162) which securely fix the stopping member (16) and the tank (17) so that the shaft seat (15), the stopping member (16) and the tank (17) become an integral part and can be rotated or stopped together. An oil outlet (151) is provided near the edge of the shaft seat (15). For accumulation of the purified oil or lubricant, the oil outlet (151) is further linked to a chamber (R) located around outside of the tank (17). An oil exit tube (R1) further connects the chamber (R) to the machine (not shown) for recycling or reuse of the purified oil or lubricant.
The driving unit (1) is used to rotate the tank (17) to separate of the contaminant and the used oil using centrifugal force, which includes a first hollow shaft (13) secured to the shaft seat (15) on the tank (17). The driving unit (1) also includes an motor (M) and two belt wheels (11, 12) which are interconnected by a looped belt. The belt wheel (11) is mounted to the turning shaft of the motor (M) and can be driven thereby. The belt wheel (12) is mounted to the first hollow shaft (13) mentioned above and can pass the power of the motor (M) to drive the first shaft (13) and thus to rotate the tank (17).
The oil-purifying mechanism (3) further comprises a second shaft (14) extends axially through and is mounted to the hollow shaft (13) for relative rotation therebetween. The second shaft (14) extends into the tank (17) and is provided with a plurality of scraping blades (32), via a base plate (31) mounted at the bottom of the second shaft (14), for scraping the contaminant which then is separated from the oil by centrifugal force and deposited on the inner peripheral wall of the tank (17).
The retaining means (2) are fixed above the aforementioned stopping member (16), which includes a stopping rod (23) inserting into a spring member (22), both of which are enclosed in a bore (211) and a space (212) formed by cylindrical casing (21). Also, the stopping member (16) has a receiving port (161) corresponding to the stopping rod (23) for the insertion of the stopping rod (23) into the receiving port (161) to retain or fix the tank (17).
When this conventional oil recovering apparatus is performing, the stop rod (23) is first lifted from the receiving port (161) so that the motor (M) could drive the shaft (13) to rotate the shaft seat (15), the stopping member (16) and the tank (17) as a whole. The used oil enters the tank (17) from the oil inlet (35) at the bottom of the tank (17) and is subjected to a centrifugal force generated by the rotation of the tank (17). Because the mass of the contaminant is larger than the oil, the matter of the contaminant is easier to deposit on the inner peripheral wall of the tank (17) and thus is separated from the oil. Afterwards, the purified oil leaves the tank (17) through the oil outlet (151) and accumulates in the chamber (R) flowing out through the exit tube (R1).
It is apparent that the sludge of contaminant deposited on the inner wall must be removed. Referring to FIG. 2, the stop rod (23) of the retaining means (2) is moved downward into the receiving port (161) to arrest the tank (17). Thereafter, the cap (14A) of the second shaft (14) is rotated manually, thus rotating the blades (32) and scraping the contaminant from the inner wall of the tank (17).
The removal process of contaminant described above is in fact not practical and not ideal. The reason is that the sludge of contaminant is generated in such a large amount and such a high rate that the contaminant removal process must generally be performed every hour or every thirty minutes in a factory. The scraping of the contaminant is carried out manually, thus if someone forgets to run the scraping blades and remove the contaminant, it may form a heavy, thick and viscous layer of sludge on the wall of the tank (17). Therefore, the rotation of the shaft (14) driven by manual labor needs huge efforts. It is also possible that the shaft (14) becomes unrotatable if the contaminant removal process is not carried out for a long time. In such a case, the tank (17) and the relevant elements in the oil recovering apparatus must be taken apart so that the accumulated sludge on the inner wall of the tank (17) can be removed.